What are swimming strategies?

it all depends on what kind of swimming you're doing. In all cases though, you should try to stay as streamlined as possible, try to pull as much water as you can with your hands, and try to keep a steady kick behind you. Also, with the kick don't just kick down into the water to make a big splash. Try to keep both of your feet under the water and create some torque by getting water resistance while moving your feet up as well as down.